The invention concerns fluid control valves, such as water control valves used in plumbing fixtures, and seals used therewith.
Valve cartridges and the like are well known for use in faucets and other plumbing fixtures. See e.g., U.S. Pat. No. 5,398,717. Generally, such valves include a cartridge housing with a valve stem that can rotate inside the housing to control a rotatable disk that moves over a stationary disk. The stationary and rotatable disks typically have holes through them that when aligned permit flow, and when completely not aligned shut off flow. These disks are preferably made of ceramic because ceramics are resistant to friction and wear and thus provide for prolonged life of the valve.
Various seals and o-rings are provided between the housing, valve stem, and stationary disk so as to prevent leaking. In particular, the seal between a plumbing fixture body and the valve cartridge housing is typically achieved by a resilient ring that seals by compression against the stationary disk and a seat of the fixture body. Insufficient compressive force can cause the valve to leak at the connection to the fixture. Too much compressive force can create undesirable resistance to rotation, making the faucet difficult to turn on or off, and increasing the rate of wear.
One attempt at addressing problems with the lower seal is disclosed in U.S. Pat. No. 6,422,268. In that patent, a valve cartridge is disclosed with a sealing ring reinforced by a reinforcing ring having a generally right angle cross-section. The sealing ring is constructed so that an end of the reinforcing ring bears against a ledge of the valve housing so that the brunt of the compressive forces are transferred to the housing rather than against the stationary control disk. The more flexible upper side of the sealing ring seals against the fixed/stationary disk of the valve under decreased loading. However, even with such a structure there are problems. In this regard, in the presence of pressure spikes the sealing ring can shear at its inner end.
Hence, a need still exists for improved cartridge type fluid control valves, particularly with respect to the structure and performance of the lower seal.